cmd/go: support `-help` #75204

Original file line number	Diff line number	Diff line change
Expand Up		@@ -109,12 +109,22 @@ func main() {
		if !cmdIsGoTelemetryOff {
		telemetry.MaybeParent() // Run the upload process. Opening the counter file is idempotent.
		}
	// Add global -help flag support
	var globalHelp bool
	flag.BoolVar(&globalHelp, "help", false, "show help")
		flag.Usage = base.Usage
		flag.Parse()
		counter.Inc("go/invocations")
		counter.CountFlags("go/flag:", *flag.CommandLine)

		args := flag.Args()

	// Handle global -help flag
	if globalHelp {
	help.Help(os.Stdout, nil)
	return
	}

		if len(args) < 1 {
		base.Usage()
		}
Expand Down Expand Up		@@ -310,12 +320,33 @@ func invoke(cmd *base.Command, args []string) {
		}
		}

	cmd.Flag.Usage = func() { cmd.Usage() }
	// Add -help flag support to all commands
	var helpFlag bool
	if !cmd.CustomFlags {
	cmd.Flag.BoolVar(&helpFlag, "help", false, "show help")
	}

	cmd.Flag.Usage = func() {
	if helpFlag {
	// Show full help like "go help <command>"
	help.Help(os.Stdout, strings.Fields(cmd.LongName()))
	base.Exit()
	} else {
	cmd.Usage()
	}
	}
		if cmd.CustomFlags {
		args = args[1:]
		} else {
		base.SetFromGOFLAGS(&cmd.Flag)
		cmd.Flag.Parse(args[1:])

	// Check if -help flag was set and show full help
	if helpFlag {
	help.Help(os.Stdout, strings.Fields(cmd.LongName()))
	base.Exit()
	}

		flagCounterPrefix := "go/" + strings.ReplaceAll(cfg.CmdName, " ", "-") + "/flag"
		counter.CountFlags(flagCounterPrefix+":", cmd.Flag)
		counter.CountFlagValue(flagCounterPrefix+"/", cmd.Flag, "buildmode")
Expand Down

62 changes: 62 additions & 0 deletions src/cmd/go/testdata/script/help_flag.txt

Show comments View file Open in desktop

Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,62 @@
	# Test that -help flag works for go commands

	# go -help shows main help (not an error)
	go -help
	stdout 'Go is a tool for managing Go source code'
	stdout 'Usage:'
	stdout 'go <command> \[arguments\]'

	# go build -help shows full help
	go build -help
	stdout 'usage: go build'
	stdout 'Build compiles the packages'
	stdout 'For more about specifying packages'

	# go install -help shows full help
	go install -help
	stdout 'usage: go install'
	stdout 'Install compiles and installs'
	stdout 'For more about specifying packages'

	# go get -help shows full help
	go get -help
	stdout 'usage: go get'
	stdout 'Get resolves its command-line arguments'
	stdout 'See also: go build, go install'

	# go fmt -help shows full help
	go fmt -help
	stdout 'usage: go fmt'
	stdout 'Fmt runs the command'
	stdout 'See also: go fix, go vet'

	# go run -help shows full help
	go run -help
	stdout 'usage: go run'
	stdout 'Run compiles and runs'
	stdout 'See also: go build'

	# go run program.go -help should pass -help to the program, not show go run help
	go run helpprog.go -help
	stdout 'Program help message'
	stdout 'Arguments: \[.helpprog.-help\]'

	-- helpprog.go --
	package main

	import (
	"flag"
	"fmt"
	"os"
	)

	func main() {
	var help = flag.Bool("help", false, "show help")
	flag.Parse()

	fmt.Printf("Arguments: %v\n", os.Args)

	if *help {
	fmt.Println("Program help message")
	}
	}

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